Vitamins Flashcards
Name and class of Vitamin A
Retinol; fat soluble
Name and class of Vitamin D
Calciferols; fat soluble
Name and class of Vitamin E
Tocopherols; fat soluble
Name and class of Vitamin K
Quinones; fat soluble
Name and class of Vitamin C
Ascorbic acid; water soluble
Name and class of Vitamin B1
Thiamin; water soluble
Name and class of Vitamin B2
Riboflavin; water soluble
Name and class of Vitamin B3
Nicotinic acid / niacin; water soluble
Name and class of Vitamin B5
Pantothenic acid; water soluble
Name and class of Vitamin B6
Pyridoxine; water soluble
Name and class of Vitamin B7
Biotin; water soluble
Name and class of Vitamin B9
Folic acid; water soluble
Name and class of Vitamin B12
Cyanocobalamin; water soluble
Metabolic function of retinol
Formation & integrity of epithelia & mucous membranes
Retinal function
- Combines with opsin to form rhodopsin needed for ‘night vision’
Bone growth
Immune function
Sources of retinol
Liver (cod liver oil)
- Accumulates and stored in the liver of animals
Egg yolk
Milk fat
Problems with deficiency of retinol in cattle
Mild deficiency - rough scaly skin
Prolonged deficiency - ‘Night blindness’, lachrymation, corneal opacity. Infertility, abortion, retained placenta, still-birth
Deficiency rare in adults as carotenoids acquired at pasture replenish hepatic stores of Vitamin A -> able to provide adequate retinol cover over winter periods (except if history of liver &/or intestinal disease)
Intensively reared indoor beef cattle on cereal diets (barley beef) are prone
Problems with deficiency of retinol in poultry
Symptoms appear quickly (2-3 weeks)
Pale comb & wattles, loss of condition, retarded growth, ruffled plumage, general unthriftiness
Susceptible to infectious diseases
High mortality rate
Poultry feeds require Vitamin A supplement
Problems with deficiency of retinol in dogs and cats
Deficiencies can occur e.g. if fed all-meat diets without liver
Dogs - scurfy, scaly skin (first sign); ‘night blindness’; abnormal skeletal growth
Cats - foetal defects are apparent & complete infertility can result
Problems with excess of retinol in dogs and cats
Abnormal bone deposition
Lameness
Vertebral spondylosis
Gingivitis
Weight loss
Poor coat
(Caused by excess fish liver oil and/or liver intakes)
Problems with excess of retinol in pigs
Excessive intakes of retinol in pregnant sows may cause cardiac abnormalities in piglets
Metabolic function of the calciferols
Promotes Ca2+ absorption from digesta in the gut lumen
When blood Ca2+ concentrations decrease, it enhances intestinal absorption of Ca
Stimulates phosphorous uptake from gut & reabsorption of both Ca2+ and P from bone and kidney
i.e. it helps regulate the amount of calcium and phosphorus in the body
Metabolism of Vit D, Calcium and Phosphorus are related
Sources of the calciferols
Sunlight on skin
Fish (oily)
Egg yolk
Hay (sun-dried roughages)
Colostrum (6-10x milk)
Problems with deficiency of the calciferols
RICKETS – soft weak deformed bones in young growing animals
Osteomalacia in adults (weak bones)
Poor egg sell quality and weak bones in poultry
Sources of α-Tocopherol
Little body reserve so dietary intake is important
Green fodder (grass, green vegetables)
Cereals (↑barley, ↓maize), but decreases rapidly during storage
Metabolic functions of α-Tocopherol
Biological antioxidant
Acts in combination with the selenium (Se) containing enzyme, glutathione peroxidase, to protect cells from oxidative damage caused by free radicals
(reactive compounds produced during cell metabolism which are capable of damaging cell membranes)
Important for normal reproductive function, muscular function & capillary integrity
Problems with deficiency of α-Tocopherol
Nutritional myopathy
-White muscle disease (calves)
-Stiff lamb diseases
Cardiac disease
-Mulberry heart disease (pigs, calves)
Brain damage
-Crazy chick disease
Lameness & muscle stiffness
-Tying-up (horses)
Sources of quinones
Green, leafy materials
Egg yolk, liver & fish
Gut bacteria synthesise
Metabolic functions of quinones
Essential for the normal clotting of blood
Bone & kidney function
Problems with deficiency of quinones
Unlikely to occur in cattle, horses or pigs
Usually no dietary requirement for ruminants as microbial population of the rumen can synthesise
Chicks: anaemia & delayed clotting of blood
Sources of B complex vitamins
Liver
Yeasts
Green foods
Cereals (+/-)
Milk (+/-)
Metabolic functions of B complex vitamins
Pathways of cellular respiration & energy transfer
Co-enzymes
Metabolic functions of thiamine
Initiation & propagation of nerve impulses
Problems with deficiency of thiamine
progressive dysfunction of the nervous system
-paralysis
-blindness
-muscular dysfunction
-Loss of appetite
-emaciation
Metabolic functions of riboflavin
Vital for oxidative phosphorylation and H+ transport
Problems with deficiency of riboflavin
Pigs: Poor appetite & growth; skin eruptions; vomiting; eye abnormalities; infertility & abortion
Chicks: ‘Curled toe paralysis’ (neural degeneration, walk on hocks)
Ruminants: Inappetance, diarrhoea, mouth lesions
Problems with deficiency of the pyridoxines
Rare due to wide distribution in many foods (inclu. milk) & gut microbial synthesis
Chicks: neural degeneration & jerky gait
Metabolic functions of cyanocobalamin
Important coenzyme in cellular respiratory pathways
Problems with deficiency of cyanocobalamin
Mostly young animals poor growth
Sources of ascorbic acid
Citrus fruits
Green, leafy vegetables
Synthetic
Metabolic functions of ascorbic acid
Normal collagen formation
Metabolic oxidation & reduction pathways
Iron transport
Antioxidant
Only essential in the diet of primates (incl. man), guinea pigs, fruit bats
Other species synthesise it from glucose
Problems with deficiency of ascorbic acid
Scurvy
-muscle and joint pain –> reluctance / difficulty moving
-lethargy
-the appearance of red dots on the skin
-bleeding and swelling of the gums
-diarrhoea
-weight loss
-rough hair coat
-reduced immune function
